Note: Descriptions are shown in the official language in which they were submitted.
1
[DESCR EPT[ON]
[TITLE OF INVENTION]
PREFORM FOR FORMING DOUBLE CONTAINER
[Technical Field]
[0001]
The present invention relates to a preform for forming a double container.
Priority is claimed on Japanese Patent Application No. 2021-073768, filed
April
26, 2021, the content of which is incorporated herein by reference.
[Background Art]
[0002]
A preform configured to form a double container including; an inner container
configured to be deformed to reduce a capacity thereof according to reduction
in contents
accommodated; and an outer container in which an inner container is installed,
and which
is provided with an outside air introduction hole through which an outside air
is
introduced between the inner container and the outer container according to
reduction in
contents, includes: a bottomed cylindrical inner preform configured to form
the inner
container; and a bottomed cylindrical outer preform configured to form the
outer
container.
As such a preform for forming a double container, for example, as disclosed in
the following Patent Document 1, a configuration in which an inner preform is
fitted into
an outer preform and a peeling agent layer is provided between an inner
peripheral
surface of the outer preform and an outer peripheral surface of the inner
preform is
known.
In the double container formed by the preform, when outside air is introduced
between the inner container and the outer container through the outside air
introduction
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2
hole according to reduction in contents, an outer peripheral surface of the
inner container
can be easily peeled off from an inner peripheral surface of the outer
container.
[Citation Listl
[Patent Document'
[0003]
[Patent Document 1]
Japanese Unexamined Patent Application, First Publication No. 2010-82916
[Summary of Invention]
[Technical Problem]
[0004]
However, in the preform for forming a double container in the related art,
since a
peeling agent layer is provided between the inner peripheral surface of the
outer preform
and the outer peripheral surface of the inner preform, there is a problem
that.
manufacturing is difficult.
[0005]
In consideration of the above-mentioned circumstances, the present invention
is
directed to providing a preform for forming a double container in which an
outer
peripheral surface of an inner container is able to be easily peeled from an
inner
peripheral surface of an outer container according to reduction in contents
even when a
peeling agent layer is not provided.
[Solution to Problem]
[0006]
The present invention employs the following means in order to solve the above-
mentioned problems. That is, a first aspect of the present invention is a
preform for
forming a double container, the double container configured to form a double
container
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3
including: an inner container configured to be deformed to reduce a capacity
according to
reduction in contacts accommodated; and an outer container in which the inner
container
is installed, and provided with an outside air introduction hole into which
outside air is
introduced between the inner container and the outer container according to
reduction in
the contents. The preform for forming a double container includes: a bottomed
cylindrical inner preform configured to form the inner container, and a
bottomed
cylindrical outer preform configured to form the outer container. The inner
preform is
inserted into the outer preform in a state in which a mouth portion of the
inner prc.µ,form is
fitted into a mouth portion of the outer preform. A longitudinal groove
extending
downward from an upper end opening edge of the outer preform is formed in an
inner
peripheral surface of the mouth portion of the outer preform. The outside air
introduction hole opens in the longitudinal groove. A flange portion
continuously
extending over an entire length in a circumferential direction, abutting an
upper end
opening edge of the outer preform, and closing an upper end opening of the
longitudinal
groove is provided on the mouth portion of the inner preform,
[00071
In the present invention, the longitudinal groove extending downward from the
upper end opening edge of the outer preform is formed in the inner peripheral
surface of
the mouth portion of the outer preform, and the outside air introduction hole
opens in the
longitudinal groove. Accordingly, even in a state in which the mouth portion
of the
inner preform is fitted into the mouth portion of the outer preform and
relative movement
between the outer preform and the inner preform is curbed. outside air passes
through the
longitudinal groove when the outside air is introduced between the inner
container and
the outer container through the outside air introduction hole. Accordingly,
even when a
peeling agent layer is not provided, the outer peripheral surface of the inner
container can
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be peeled off from the inner peripheral surface of the outer container
according to
reduction in contents.
The longitudinal groove extends downward from the upper end opening edge of
the outer preform. Accordingly. the longitudinal groove can be easily provided
in the
inner peripheral surface of the outer preform without complicating the
structure of the
molding die.
A flange portion continuously extending over the entire length in the
circumferential direction and abutting the upper end opening edge of the outer
preform is
provided on the mouth portion of the inner preform. Accordingly, relative
movement
between the outer preform and the inner preform can he reliably suppressed.
The Flange portion closes the upper end opening of the longitudinal groove.
Accordingly, according to reduction in contents, a portion into which the
outside air
enters between the inner container and the outer container can be limited to
the outside
air introduction hole. Accordingly, it becomes easier to maintain the momentum
when
the outside air enters between the inner container and the outer container,
the outer
peripheral surface of the inner container can be reliably easily peeled off
from the inner
peripheral surface of the outer container, and it is possible to easily make
the contracted
deformation state of the inner container into a desired shape. As a result, it
is possible
to reduce the remaining amount of contents.
[0008]
A second aspect of the present invention is the preform for forming a double
container of the above-mentioned first aspect in which, when seen in a
longitudinal
cross-sectional view along a central axis of the inner preform, an inner
peripheral surface
and an outer peripheral surface of the mouth portion of the inner preform
extends along
the central axis.
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[0009]
In this case, the inner peripheral surface and the outer peripheral surface of
the
mouth portion of the inner preform extend along the central axis when seen in
a
longitudinal cross-sectional view along a central axis of the inner preform.
Accordingly, relative movement between the outer preform and the inner preform
can he
reliably suppressed.
[0010]
A third aspect of the present invention is the preform for forming a double
container of the above-mentioned first or second aspect in which a projection
portion
protruding outward in a radial direction, continuously extending over the
entire length in
the circumferential direction, and pressed against the inner peripheral
surface of the
mouth portion of the outer preform, is provided in the outer peripheral
surface of the
mouth portion of the inner preform.
[0011]
In this case, the projection portion pressed against the inner peripheral
surface of
the mouth portion of the outer preform is provided on the outer peripheral
surface of the
mouth portion of the inner preform. Accordingly, relative movement between the
outer
preform and the inner preform can be reliably suppressed.
[0012]
A fourth aspect of the present invention is the preform for forming a double
container of the above-mentioned first to third aspects in which a diffusion
gap
continuously extending over the entire length in the circumferential
direction, is provided
between a connecting portion to a lower surface of the flange portion in the
outer
peripheral surface of the inner preform and a connecting portion to the inner
peripheral
surface and the upper end opening edge of the outer preform.
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1_00131
In this case, the diffusion gap is provided between the connecting portion to
the
lower surface of the flange portion of the outer peripheral surface of the
inner preform
and the connecting portion to the inner peripheral surface and the upper end
opening
edge of the outer preform. Accordingly, as the outside air introduced between
the inner
container and the outer container through the outside air introduction hole
flows through
the diffusion gap according to reduction in contents, it spreads more easily
over the entire
length in the circumferential direction in the mouth portion of the double
container, and
the contracted deformation state of the inner container can he easily made
into a desired
shape.
[Effects of invention]
[00141
According to the present invention, even when a peeling agent layer is not
provided, the outer peripheral surface of the inner container can be easily
peeled off from
the inner peripheral surface of the outer container according to reduction in
contents.
[Brief Description of Drawings]
[00151
FIG, 1 is a plan view of a preform for forming a double container shown as an
embodiment.
FIG. 2 is a half longitudinal cross-sectional view including a cross section
along
an arrow H according to a first embodiment of FIG. 1.
FIG. 3 is a cross-sectional view along an arrow III according to the first
embodiment of FTG. 1.
FIG. 4 is a cross-sectional view along an arrow IV according to the first
embodiment of FIG. 1 ,
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FIG, 5 is a cross-sectional view along an arrow III according to a second
embodiment of FIG. 1.
FIG. 6 is a cross-sectional view along an arrow IV according to the second
embodiment.
[Description of Embodiments]
[0016]
Hereinafter, a preform for forming a double container according to a first
embodiment will he described with reference to the accompanying drawings. As
shown
in 141G. I to FIG. 4, a preform I for forming a double container is used to
form a double
container X including an inner container X1 deformed to reduce a capacity
thereof
according to reduction in contents accommodated and an outer container X2, in
which
the inner container X1 is installed, is provided with an outside air
introduction hole 13
configured to introduce outside air between the inner container X1 and the
outer
container X2 according to reduction in contents.
The double container X is formed by blow-molding the preform 1 for forming a
double container, In the double container X, the inner container X1 is highly
flexible
arid is provided so as to be separated from an inner surface of the outer
container X2.
[00171
The preform 1 for forming a double container includes a bottomed cylindrical
inner preform 11 configured to form the inner container Xi, and a bottomed
cylindrical
outer preform 12 configured to form the outer container X2. In FIG. 1, the
inner
preform 11 is hatched.
As shown in FIG. 2, a mouth portion (hereinafter, referred to as an inner
month
portion) .21 of the inner preform 11 is inserted into a mouth portion
(hereinafter. referred
to as an outer mouth portion) 22 of the. Outer preform 12, and a bottom
portion
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(hereinafter, referred to as an inner bottom portion) 23 of the inner preforni
11 is inserted
into a bottom portion (hereinafter, referred to as an outer bottom portion) 24
of the outer
preform 12.
[00181
The inner preform 11 and the outer preform 12 are disposed coaxially with a
common axis. Hereinafter, the common axis is referred to as a central axis 0.
the itmer
mouth portion 21 side and the outer mouth portion 22 side along the central
axis 0 are
referred to as upper sides, and the inner bottom portion 23 side and the outer
bottom
portion 24 side along the central axis 0 are referred to as lower sides. When
seen in an
upward/downward direction, a direction crossing the central axis 0 is referred
to as a
radial direction, and a direction around the central axis 0 is referred to as
a
circumferential direction,
[0019]
Materials of the inner preform 11 and the outer preform 12 are synthetic resin
materials, which may be the same material or different materials. As an
example of the
synthetic resin material, for example, polyethylene terephthalate (PET),
polypropylene
(PP), polyethylene (PE), polyamide (Nylon), ethylene-vinyl alcohol copolymer
(FNOH),
and the like, are exemplified.
[0020]
As shown in FIG. 4, the inner mouth portion 21 is fitted inside the outer
mouth
portion 22. An outer peripheral surface of the inner mouth portion 21 abuts an
inner
peripheral surface of the outer mouth portion 22 throughout the entire length
in the
upward/downward direction.
As shown in FIG. 2, a gap is provided at a portion located below the inner
month portion 21 and the outer mouth portion 22 between the outer peripheral
surface of
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the inner preform 11 and the inner peripheral surface of the outer preform 12
throughout
the entire length in the upward/downward direction.
[00211
A male screw portion 22a on which a cap (not shown) is screwed, a protrusion
to
be sealed .2213 onto which a circumferential wall portion of the cap (not
shown) is fitted,
and a neck ring 22c are formed on an outer peripheral surface of the outer
mouth portion
22 from above toward below in sequence.
Further, the cap may he undercut-fined onto the outer mouth portion 22.
[0022]
The protrusion to be sealed 22h and the neck ring 2.2c protrude outward from
the
outer mouth portion 22 in the radial direction and continuously extend
throughout the
entire length in the circumferential direction. A space between the outer
peripheral
surface of the protrusion to be sealed 22b and the inner peripheral surface or
the
circumferential wall portion of the cap (not shown) is hermetically sealed. An
outer
diameter of the neck ring 22c is greater than an outer diameter of the
protrusion to be
sealed 22b. The neck ring 22c is located below a circumferential wall portion
of the cap
(not shown).
[00231
The above-mentioned outside air introduction hole 13 is formed in the outer
mouth portion 22. The outside air introduction hole 13 is located on the
outermost side
of the protrusion to be sealed 22b in the radial direction, and located above
a seal surface
continuously extending over the entire length in the circumferential
direction. Positions
of lower portions of the outside air introduction hole 13 and the male screw
portion .22a
in the upward/downward direction are the same as each other. Here, the male
screw
portion 22a extends intermittently in the circumferential direction, and 1.he
outside air
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introduction hole 13 is provided in an intermittent portion of the male screw
portion 22a
in the circumferential direction.
A longitudinal groove 16 extending downward from an upper end opening edge
15 of the outer preform 12 is formed in an inner peripheral surface of the
outer mouth
portion 2.2. The outside air introduction hole 13 is open in the longitudinal
groove 16.
A lower end portion of the longitudinal groove 16 is located below the neck
ring 22c.
[0024]
As shown in FIG. 1, each of the outside air introduction hole 13 and the
longitudinal groove 16 is provided in plurality at the same interval in the
circumferential
direction. In the example shown, the longitudinal grooves 16 are provided at
four
places at an interval of 90 about the central axis 0 when seen in the
upward/downward
direction. In the four longitudinal grooves 16, each or the two longitudinal
grooves 16
facing each other in the radial direction has the outside air introduction
hole 13 that is
open. Further, the outside air introduction holes 13 may be open in all the.
longitudinal
grooves 16, or the plurality of outside air introduction holes 13 may be open
in one
longitudinal groove 16.
[0025]
A flange portion 25 continuously extending over the entire length in the
circumferential direction and abutting the upper end opening edge 15 of the
outer
preform 12 is provided in the inner mouth portion 21. As shown in FIG. 3, the
flange
portion 25 closes an upper end opening of the longitudinal groove 16.
[00.26]
As shown in FIG. 4, a projection portion 26 protruding outward in the radial
direction, continuously extending over the entire length in the
circumferential direction
and press-fitted into an inner peripheral surface of the outer mouth portion
22 is provided
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11
in an outer peripheral surface of the inner mouth portion 21. The plurality of
projection
portions 26 are provided at an interval in the upward/downward direction. As
shown in
FIG. 3, the projection portion 26 is located above the outside air
introduction hole 13 of
the outer mouth portion 22. Further, the projection portion 26 may not be
provided.
[00.27]
The inner peripheral surface and the outer peripheral surface of the inner
mouth
portion 21 extend along the central axis 0 when seen in a longitudinal cross-
sectional
view atomg the central axis 0. In the inner peripheral surface and the outer
peripheral
surface of the inner mouth portion 21, at least the inner peripheral surface
extends in
parallel with the central axis 0. In the example shown, the inner peripheral
surface and
the outer peripheral surface of the inner mouth portion 21 extend in parallel
with the
central axis 0. "Parallel" disclosed herein includes a draft angle from a
molding die.
[0028]
The inner mouth portion 21 is a portion of the inner preform 11 including the
same position in the upward/downward direction in the outer preform 12 with
respect to
the lower surface of the neck ring 22c and located above the lower surface. In
the
preform 1 for forming a double container, the portion that includes the same
position in
the upward/downward direction and is located above the lower surface of the
neck ring
22c is a portion that does not change shape before and after blow molding.
[0029]
In the outer peripheral surface of the inner preform 11. a plurality of ribs
11 a
protruding outward in the radial direction, adjacent to an inner peripheral
surface of the
outer preform 1.2 are formed at a portion continuous with a lower end of the
inner mouth
portion 21 at an interval in the circumferential direction. The ribs 11 a
maintain a
communication state in the upward/downward direction between the outer
peripheral
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12
surface of the inner container X1 and the inner peripheral surface of the
outer container
X2 in the double container X.
Further, the ribs ha may be a portion whose shape does not change before and
after blow molding, or may be a portion that contacts the inner peripheral
surface of the
outer container X.2 formed by the outer preform 12 after blow molding.
[0030]
A diffusion gap A continuously extending over the entire length in the
circumferential direction is provided between a connecting portion to a lower
surface of
the flange portion 25 in the outer peripheral surface of the inner preform 11
and a
connecting portion to the inner peripheral surface and the upper end opening
edge 15 of
the outer preform 12. The diffusion gap A opens in the longitudinal groove 16.
The connecting portion to the lower surface of the flange portion 25 in the
outer
peripheral surface of the inner preform 11 is formed in a curved surface shape
recessed
inward in the radial direction. The connecting portion to the inner peripheral
surface
and the upper end opening edge 15 of the outer preform 1.2 is Formed in a
curved surface
shape protruding inward in the radial direction.
[0031]
As described above, according to the preform 1 for forming a double container
by the embodiment, the longitudinal groove 16 extending downward from the
upper end
opening edge 15 of the outer preform 12 is formed in the inner peripheral
surface of the
outer mouth portion 22, and the outside air introduction hole 13 opens in the
longitudinal
groove 16. Accordingly, even in a state in which the inner mouth portion 21 is
fitted
into the outer mouth portion 22 and relative movement between the outer
preform 12 and
the inner preform 11 is suppressed, the outside air passes through the
longitudinal groove
16 when the outside air is introduced between the inner container X1 and the
outer
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13
container X2 through the outside air introduction hole 13. Accordingly, even
when the
peeling agent layer is not provided, the outer peripheral surface of the inner
container X1
can be easily peeled off from the inner peripheral surface of the outer
container X2
according to reduction in contents.
[0032]
The longitudinal groove 16 extends downward from the upper end opening edge
of the outer preform 12. Accordingly, the longitudinal groove 16 can be easily
provided on the inner peripheral surface of the outer preform 12 without
complicating the
structure of the molding die.
10 The flange portion 25 continuously extending over the entire length
in the
circumferential direction and abutting the upper end opening edge 15 of the
outer
preform 12 is provided in the inner mouth portion 21. Accordingly, relative
movement
between the outer preform 12 and the inner preform 11 can be reliably
suppressed.
[0033]
15 The flange portion 25 closes the upper end opening of the
longitudinal groove
16. Accordingly, a portion into which the outside air enters
between the inner container
X1 and the outer container X2 can be limited to the outside air introduction
hole 13
according to reduction in contents. Accordingly, it becomes easier to maintain
the
momentum when the outside air enters between the inner container X1 and the
outer
container X2, it becomes easier to peel off the outer peripheral surface of
the inner
container X1 from the inner peripheral surface of the outer container X2, and
at the same
time, it is possible to make the contracted deformation shape of the inner
container X1
easy to achieve the desired shape. As a result, it is possible to suppress the
remaining
amount of the contents.
[0034]
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The inner peripheral surface and the outer peripheral surface of the inner
mouth
portion 21 extend along the central axis 0 when seen in a longitudinal cross-
sectional
view along the central axis O. Accordingly, relative movement between the
outer
preform 12 and the inner preform 11 can be reliably suppressed.
[0035]
The projection portion 26 pressed against the inner peripheral surface of the
outer mouth portion 22 is provided on the outer peripheral surface of the
inner mouth
portion 21. Accordingly, relative movement between the outer preform 12 and
the inner
preform 11 can be reliably suppressed.
[0036]
The diffusion gap A is provided between the connecting portion to the lower
surface of the flange portion 25 in the outer peripheral surface of the inner
preform 11
and the connecting portion to the inner peripheral surface and the upper end
opening
edge 15 of the outer preform 12. Accordingly, as the outside air introduced
between the
inner container X1 and the outer container X2 through the outside air
introduction hole.
13 flows through the diffusion gap A according to reduction in contents, it
becomes easy
to spread over the entire length in the circumferential direction in the mouth
portion of
the double container X, and it is possible to easily make the contracted
deformation shape
of the inner container X1 into the desired shape.
[0037]
Next, a preform 1 for forming a double container according to a second
embodiment will he described with reference to FIG. 5 and FIG. 6.
Further, in the second embodiment, parts that are the same as the components
in
the first embodiment are designated by the same reference numerals,
descriptions thereof
are omitted, and only different points will he described.
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15
[00381
In the embodiment, the ribs lla abut the inner peripheral surface of the outer
preform 12. Positions of upper end portions of the ribs 11a and a lower end
portion of
the longitudinal groove 16 in the upward/downward direction are the same as
each other.
Lower end portions of the ribs lla are located below the longitudinal groove
16.
In the preform 1 for forming a double container, an abutting portion of the
ribs
ha abutting the inner peripheral surface of the outer preform 12 is located at
a boundary
between a portion whose shape does not change before and after blow molding
and a
portion extending upon blow molding.
LU Further, in the. preform 1 for forming a double container, the inner
mouth portion
21, and the abutting portion of the ribs lla and the portion where positions
in the
upward/downward direction are the same may be the portion whose shape does not
change before and after blow molding, and the portion located below the
abutting portion
of the ribs 11 a may be the portion extending upon blow molding,
[0039]
As described above, according to the preform 1 for forming a double container
by the embodiment, even when the peeling agent layer is not provided like the
preform 1
for forming a double container, the outer peripheral surface of the inner
container X1 can
be easily peeled off from the inner peripheral surface of the outer container
X2 according
to reduction in contents.
[0040]
Further, the technical scope of the present invention is not particularly
limited to
the above-mentioned embodiment, and various modifications may he made without
departing from the spirit of the present invention.
[0041]
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16
The diffusion gap A may not be provided between the connecting portion to the
lower surface of the flange portion 25 in the outer peripheral surface of the
inner preform
11 and the connecting portion to the inner peripheral surface and the upper
end opening
edge 15 of the outer preform 12.
[0042]
In addition, the components in the embodiment can be appropriately replaced
with well-known components, and the embodiment and the variant may be combined
as
appropriate without departing from the spirit of the present invention,
[Industrial Applicability]
[0043]
According to the present invention, even when the peeling agent layer is not
provided, the outer peripheral surface of the inner container can be easily
peeled off from
the inner peripheral surface of the outer container according to reduction in
contents.
[Reference Signs 1,ist]
[0044]
1, 2 Preform for forming double container
11 Inner preform
12 Outer preform
13 Outside air introduction hole
15 Upper end opening edge
16 Longitudinal groove
21 Inner mouth portion (mouth portion of inner preform)
22 Outer mouth portion (mouth portion of outer preform)
Flange portion
25 26 Projection portion
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A Di ifusion gap
0 Central axis
X Double container
X1 Inner container
X2 Outer container
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